Numerous types of crutches are known for providing mobility to those who suffer from infirmities, injuries, and/or handicaps. Hands-free crutches are particularly useful because they allow their users to use both hands for tasks other than stabilizing the crutch.
The earliest hand-free crutches appear to have relied on monopods, i.e., a single ground contact pad that is substantially flat on the bottom. See e.g., U.S. Pat. No. 1,185,906 to Hoff (1916) and U.S. Pat. No. 2,827,897 to Pawlowki (1956). That strategy has persisted into the present, as exemplified by U.S. Pat. No. 3,074,420 to Gottman (1963), U.S. Pat. No. 4,058,119 to Rosequist (1977), U.S. Pat. No. 5,178,595 to MacGreggor (1993), U.S. Pat. No. 5,575,299 to Bieri (1996), U.S. Pat. No. 6,494,919 to Matthews (2002), and U.S. Pat. No. 7,600,524 to West (2009).
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Starting in the mid-1990s three appears to have been recognition that a single foot was not satisfactory, and the field began experimenting with use of a second foot. See e.g., U.S. Pat. No. 5,746,236 to Tilsey (1998), U.S. Pat. No. 6,799,592 and Reynolds (2004). Other variations to improve stability have included a single foot having a width that extends from the medial to the lateral side of the user's foot, and even a three-footed crutch, see the Freedom Leg™ (2011) and US2007.0241560 to Moore (publ 2007), respectively.
Unfortunately, these and all other known hands-free crutches are difficult to use due to lack of stability and/or lack of natural transfer of weight. The user must re-learn a new way of transferring weight to and from the crutch while walking. Thus, there is still a need for stable hands-free crutch, which allows the user to walk in a relatively natural manner.